1. Field of the Invention
The present invention is generally related to the machining of cylindrical parts and particularly to electrical discharge machining of grooves in cylindrical parts.
2. General Background
In some industries it is required that tubular members have one or more grooves around the inner or outer diameter of the tubular members. Patents directed to the use of electric discharge machining (EDM) or some type of erosion for cutting members or forming notches or grooves that applicant is aware of include the following.
U.S. Pat. No. 4,948,933 discloses a portable electrode arc cutting tool that is releasably attachable to the work surface for cutting an internal or external precision depth notch in the work surface. The electrode member extends over a distance equal to the length of the notch to be formed. The depth of the notch is controlled by a calibrated feed control that limits the radial movement of the electrode.
U.S Pat. No. 4,476,368 discloses a metal tube wall disintegrator where the electrode moves in a path that mechanically opens and closes the circuit by alternately contacting and retracting the electrode from the work piece to produce the electrical spark erosion.
U.S. Pat. No. 4,203,018 discloses an electrode mounted on horizontal slides fed outward with a cam mechanism. U.S. Pat. No. 4,104,503 discloses an apparatus for electroerosion within a solid component where two linkage members slide relative to each other to rotate the electrode into the work.
U.S. Pat. No. 4,100,388 discloses an electroerosion method and apparatus where two electrodes are used, with the path of one electrode intersecting that of the other electrode to create a dovetail channel.
The known art of electrical discharge machining leaves a need for an apparatus capable of providing a circumferential groove around the interior or exterior diameter of a tubular member.